In the previous art, the heavy lift trucks hoppers such as for example, mining trucks, mainly are constituted by flat surfaces and a combination of varied types of beams which stiffen the planes forming the box container.
Also, there are hoppers of various proportions, curved, rigid and deformable of steel and rubber surfaces. All of them are curved in cross direction wherein a framework of beams also in a cross direction, in some cases rigid in others flexible, provide a structure supporting the curves of the sheet.
There are several patent documents disclosing sad types of hoppers. Thus, for example, document CL 3486-2000 published also as WO 02/49879 discloses a truck bed hopper of a mining dump truck that is capable of elastic deformation when it is subject to the loading or unloading of material, built preferably of structural or of wear steel, where the general structure of the bed hopper is curved. In this way, the great moments of inertia which are achieved with curved surfaces eliminate or reduce to a great extent the use of beams as main resistive elements. The present bed hopper has a protective blinder which is preferably cylindrical in shape and a frontal wall and floor are preferably elliptical in shape. The bottom of the bed hopper externally has a plurality of transversal beams which have the main function of keeping the bottom surface curved and transferring the strengths of the envelopment to the truck's body. Further, the bottom externally also has a plurality of support elements, preferably two in number, that are located at the front part, i.e., ahead of the rotation axis of the hopper. Said support elements only permit the support of the bed hopper on the truck's body and may be eliminated if the truck's body adapts itself to directly take in the transversal beams.
Document CL 0385-1996 discloses a mining hopper for transport of material comprising a structure formed by the hopper itself or a box integrally manufactured from a wear steel being itself the floor, the side walls and the front part, the only coating against abrasion and a reinforcement structure formed by a plurality of “T” beams arranged adjacent to the box, either longitudinal or in cross direction such that it can provide structural support to the box, structure which also is only made from wear material.
Document CL 0015-1999 discloses a high mobile efficiency box which structure framework is formed by “U” folded beams, constructed in six different types of steels, located in different zones according to the mechanical requirements; having a structural portion of its angle side cross members relative to the floor and with respect to the chassis and incorporating a zone in which the gases exiting the truck are taken advantage of making them pass through the structure formed by “U”-shaped beams, heating the containing box throughout all its surface.
Document CL 0873-2003 which was also published as EP 1473189 discloses a mining hopper aimed to transport sterile materials and ores having a mixed structure based on polymers and steels which constitute the body of the hopper for transporting the material. It comprises a floor, side walls, front section and side plates, visor and external areas manufactured of polymers or polymers parts.
Document CL 0327-2010 discloses a hopper to be installed on mining trucks, it comprises a V-shaped floor having curved ends, two side walls, a front wall and a visor, a plurality of H-shaped beams arranged in an horizontal, vertical and adjacent manner which form the framework, thus allowing to fix the floor, the two side walls, the front wall and the visor.
Document CL 1878-2009 also published as AU2010224359 discloses a folded hopper for a mining truck having a floor made of an anti-abrasive material which increases its resistance and simplifies manufacturing work, it is manufactured from special steels. Said anti-abrasive material is folded and of small thickness, with its sides folded, it only uses large beams on the sides.
Document CL 0241-2011 discloses an aerodynamic hopper for high tonnage trucks constructed with double beams in “1” which form a single structure for fixing the floor, the front section and side walls, a flat floor formed by a steel sheet attached to the beams, side walls, and front section formed by a S-shaped sheet and a visor attached to the front section and beams.
Document DE10140587 discloses a tipper body having a front wall, a protective shield, and a base of curved sections, consisting of a plurality of transverse bars, preferably 4-6 curved transverse bars on the base, and at least one curved transverse bar and two side bars on said protective shield. The curved surface of the shield is preferably cylindrical, and surfaces of shield and base are preferably elliptical. There are also two longitudinal support elements to support the tipper body on the truck chassis. The material for the body sections is wear-resistant steel or conventional steel.
Document US 2002/0180247 discloses a hopper box for use in off-road transport vehicle having rubber tires, it comprises a curved floor with a front part, rear part and a pair of side edges extending between the front part and the end part. The plant includes a lower surface adapted for the fundamental connection with the transport vehicle. Each one of the side walls includes a front part and each one of said side walls can be curved. A curved front wall is attached to the front part of the plant and to the front part of each one of the side walls. Therefore, the floor, side walls and front wall cooperate to define a useful cargo space.
Generally, throughout the previous art are described different types of hoppers in which the closest to the present invention are those which walls and floors have a concave curvature in cross direction of the hopper box.